<template>
  <div class="goods-sku">
    <dl v-for="item in goods.specs" :key="item.id">
      <dt>{{ item.name }}</dt>
      <dd>
        <template v-for="val in item.values" :key="val.name">
          <img
            :class="{ selected: val.selected, disabled: val.disabled }"
            @click="clickSpecs(item, val)"
            v-if="val.picture"
            :src="val.picture"
          />
          <span
            :class="{ selected: val.selected, disabled: val.disabled }"
            @click="clickSpecs(item, val)"
            v-else
            >{{ val.name }}</span
          >
        </template>
      </dd>
    </dl>
  </div>
</template>
<script lang="ts">
import { defineComponent, PropType } from 'vue'
import getPowerSet from './power-set'
const spliter = '★'
// 根据skus数据得到路径字典对象
type Sku = {
  id: string
  inventory: string
  oldPrice: string
  price: string
  skuCode: string
  specs: {
    name: string
    valueName: string
  }[]
}

type Skus = Sku[]
const getPathMap = (skus: Skus) => {
  const pathMap = {} as any
  skus.forEach((sku) => {
    // 1. 过滤出有库存有效的sku
    if (sku.inventory) {
      // 2. 得到sku属性值数组
      const specs = sku.specs.map((spec) => spec.valueName)
      // 3. 得到sku属性值数组的子集
      const powerSet = getPowerSet(specs)
      // 4. 设置给路径字典对象
      powerSet.forEach((set) => {
        const key = set.join(spliter)
        // 如果没有就先初始化一个空数组
        if (!pathMap[key]) {
          pathMap[key] = []
        }
        pathMap[key].push(sku.id)
      })
    }
  })
  return pathMap
}

type ValueItem = {
  desc: string
  disabled: boolean
  name: string
  picture: string
  selected: boolean
}
type Spec = {
  id: string
  name: string
  values: ValueItem[]
}
type Specs = Spec[]
function initDisabledStatus(specs: Specs, pathMap: any) {
  specs.forEach((spec) => {
    spec.values.forEach((val) => {
      // 设置禁用状态
      val.disabled = !pathMap[val.name]
    })
  })
}

// 得到当前选中规格集合

const getSelectedArr = (specs: Specs) => {
  const selectedArr: any[] = []
  specs.forEach((spec, index) => {
    const selectedVal = spec.values.find((val) => val.selected)
    if (selectedVal) {
      selectedArr[index] = selectedVal.name
    } else {
      selectedArr[index] = undefined
    }
  })
  return selectedArr
}

// 更新按钮的禁用状态
const updateDisabledStatus = (specs: Specs, pathMap: any) => {
  // 遍历每一种规格
  specs.forEach((item, i) => {
    // 拿到当前选择的项目
    const selectedArr = getSelectedArr(specs)
    // 遍历每一个按钮
    item.values.forEach((val) => {
      if (!val.selected) {
        selectedArr[i] = val.name
        // 去掉undefined之后组合成key
        const key = selectedArr.filter((value) => value).join(spliter)
        val.disabled = !pathMap[key]
      }
    })
  })
}
type Goods = {
  specs: Spec[]
  skus: Sku[]
}
// 初始化选中状态
const initSelectedStatus = (goods: Goods, skuId: string) => {
  // 找到当前的sku对象
  const sku = goods.skus.find((sku) => sku.id === skuId)
  if (sku) {
    goods.specs.forEach((item, i) => {
      const val = item.values.find((val) => val.name === sku.specs[i].valueName)
      val!.selected = true
    })
  }
}

export default defineComponent({
  name: 'XtxGoodSku',
  props: {
    // specs:所有的规格信息  skus:所有的sku组合
    goods: {
      // skus需要有严格的item类型,否则使用原生数组方法会报never类型！！！
      type: Object as PropType<{ specs: Spec[]; skus: Sku[] }>,
      default: () => ({ specs: [], skus: [] }),
    },
    // 当前所有商品规格组成的有效skuId(唯一标识)
    skuId: {
      type: String,
      default: '',
    },
  },
  emits: ['change'],
  setup(props, { emit }) {
    // 得到所有字典集合
    const pathMap = getPathMap(props.goods.skus)
    // 组件初始化的时候更新禁用状态
    initDisabledStatus(props.goods.specs, pathMap)
    // 根据传入的skuId默认选中规格按钮
    if (props.skuId) {
      initSelectedStatus(props.goods, props.skuId)
    }
    const clickSpecs = (item: Spec, val: ValueItem) => {
      if (val.disabled) return false
      // 选中与取消选中逻辑
      if (val.selected) {
        val.selected = false
      } else {
        item.values.forEach((bv) => {
          bv.selected = false
        })
        val.selected = true
      }
      // 点击之后再次更新选中状态
      updateDisabledStatus(props.goods.specs, pathMap)
      // 把选择的sku信息传出去给父组件
      // 触发change事件将sku数据传递出去
      const selectedArr = getSelectedArr(props.goods.specs).filter(
        (value) => value
      )
      // 如果选中得规格数量和传入得规格总数相等则传出完整信息(都选择了)
      // 否则传出空对象
      if (selectedArr.length === props.goods.specs.length) {
        // 从路径字典中得到skuId
        const skuId = pathMap[selectedArr.join(spliter)][0]
        const sku = props.goods.skus.find((sku) => sku.id === skuId) as Sku
        // 传递数据给父组件
        emit('change', {
          skuId: sku.id,
          price: sku.price,
          oldPrice: sku.oldPrice,
          inventory: sku.inventory,
          specsText: sku.specs
            .reduce((p: string, n: any) => `${p} ${n.name}：${n.valueName}`, '')
            .trim(),
        })
      } else {
        emit('change', {})
      }
    }
    return { clickSpecs }
  },
})
</script>

<style scoped lang="less">
@import '@/styles/var.less';
.sku-state-mixin () {
  border: 1px solid #e4e4e4;
  margin-right: 10px;
  cursor: pointer;
  &.selected {
    border-color: @xtxColor;
  }
  &.disabled {
    opacity: 0.6;
    border-style: dashed;
    cursor: not-allowed;
  }
}
.goods-sku {
  padding-left: 10px;
  padding-top: 20px;
  dl {
    display: flex;
    padding-bottom: 20px;
    align-items: center;
    dt {
      width: 50px;
      color: #999;
    }
    dd {
      flex: 1;
      color: #666;
      > img {
        width: 50px;
        height: 50px;
        .sku-state-mixin ();
      }
      > span {
        display: inline-block;
        height: 30px;
        line-height: 28px;
        padding: 0 20px;
        .sku-state-mixin ();
      }
    }
  }
}
</style>
